Abstract: The difference between the phases of superconducting order parameter plays insuperconducting circuits the role similar to that played by the electrostaticpotential difference required to drive a current in conventional circuits. Thisfundamental property can be altered by inserting in a superconducting circuit aparticular type of weak link, the so-called Josephson $\pi$-junction havinginverted current-phase relation and enabling a shift of the phase by $\pi$. Wedemonstrate the operation of three superconducting circuits - two of them areclassical and one quantum - which all utilize such $\pi$-phase shiftersrealized using superconductor-ferromagnet-superconductor sandwich technology.The classical circuits are based on single-flux-quantum cells, which are shownto be scalable and compatible with conventional niobium-based superconductingelectronics. The quantum circuit is a $\pi$-phase biased qubit, for which weobserve coherent Rabi oscillations and compare the measured coherence time withthat of conventional superconducting phase qubits.